With regard to such a vehicle light source unit as described above, a vehicle light source unit disclosed in PLT 1, described below, is known. In the technology disclosed in PLT 1, a light emitting diode as the light-emitting portion and a projection lens as the optical portion are supported by a metal-made light source supporting block and a plurality of light source supporting blocks are supported by a common, metal-made supporting member. Accordingly, in the technology disclosed in PLT 1, heat generated by each of the light emitting diodes is transferred to the metal-made supporting member through the intermediary of the light source supporting block that is formed of metal and has a high heat conductivity, so that temperature rising in the light emitting diode is suppressed.